Rufus Sewell does not want to be typecast – on stage or off. He has played romantic heroes (Will Ladislaw in the BBC's 'Middlemarch'), an Italian detective (in 'Zen', the BBC's adaptation of Michael Dibdin's crime novels) and even had a go at being a vampire (in the film 'Abraham Lincoln: Vampire Hunter'). In 2006, he won an Olivier award starring in Tom Stoppard's 'Rock'n'Roll'. At 45, he has the looks of a romantic hero mixed with an inveterate laddishness. He has a marvellously level stare.

At drama school, he was always cast in comedies: "I made people laugh." I can believe this because over lunch in Kensington, his colossal self-deprecation makes me laugh too. And yet, as he admits, he is "tricky". Unusually for an actor, he is more relaxed talking about his personal than his professional life.

He is about to star in Harold Pinter's 'Old Times', directed by Ian Rickson in a three-hander with Lia Williams and Kristin Scott Thomas, who swap roles on alternate nights. This experiment, Sewell explains, unlocks the play. But he stalls when asked about Pinter, as if fearful of making a compromising gaffe: "I don't like people who wear their style on their sleeves," he says. But he does admit that rehearsing the part of Deeley has made him feel a "knot in my stomach as if I was at the worst stage of a relationship". Fortunately, there is room for comedy, too. Deeley's most quoted line is: "You have a wonderful casserole – I mean, wife." I try to coax Sewell into saying this over lunch. He declines.

He is based in Los Angeles, which, he maintains, has boosted his career over here. "Whenever I unpack in a place, the work dries up." LA is about quiet nights in with his girlfriend: "Hollywood is my domestic idyll." But more than his career brings him to London. His 10-year-old son lives there. Does being a father make him feel differently about his own childhood? "I am conscious that I was 10 when my father [an animator] died. My feelings about my mortality are less selfish than they used to be. I used to affect a cavalier attitude to death; now I see it from my son's perspective."

Sewell has described himself as a difficult teenager but his wilder side these days is on hold (he has been on the wagon for years). "I used to get in my own way. I am a lot fitter now and more alive." Yet he does seem to thrive on his own insecurities. He talks about unemployment and a talent for making "gravy soup". Let us just hope that casting directors keep him out of the kitchen for years to come.